I was wondering if there has been any research conducted on this issue. That is, all other things being equal how much more likely is a professed supporter of a political party or politician to support a position taken by that person or body, as opposed to the general likelihood of a person of that demographic. Specifically, how much does the political party's position influence that person, rather than how much more likely are they to affiliate to a party who already supports it...
As a hypothetical example, if we take say that an upper-middle class person (we could use the B-grade socio-economic status grouping if we were so minded) in a fairly cosmopolitan area, with a second degree level education, who spends around 25 hours per week on political research and say they might be 55% likely to support unlimited immigration. If we were to poll them and state that a political party/leader they specifically affiliate with opposes immigration, might we expect that to fall to 50%, 45%, 20%? Does any alteration in support vary by political affiliation, and by specific issue, or by political affiliation in concert with the specific issue concerned?
I'm looking for research with questions similar to the following combination:
"Do you support [X]?"
"[Your political party or leader here] supports [X]. Do you support [X]?"
Where [X] is the same political issue for both questions. The questions might be asked of the same person one after the other, or the questions might be asked of two randomised samples with the same professed party affiliation.
Has there been any research done on this subject?